Pressure-fluid motor.



G. H. GILMAN.

PRESSURE FLUID MOTUR. APPLicATmN msn MAR. so. w14.

1,250,932. Patented De@ 18, 1.917..

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Georgen Gzllwnan,

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GEORGE H. GILMAN, 0F CLAREMONT, NEW HAMPSHIRE, ASSIGNOR T0 SULLIVAN'MACHINERY COMPANY, 0F BOSTON, MASSACHUSETTS, A CORPORATION OFMASSACHUSETTS.

. PBESSUREFLUID MOTOR.

Patented Dec. 1s, 1917.

Application led March 30, 1914. SeriaI No. 828,155.

To all whom 'it may concern:

Be it known that I, GEORGE H. GILMAN, a citizen of the United States,and a resident of Claremont, Sullivan county, New Hampshire, haveinvented an Improvement in PressureFluid Motors, of which the followingdescription, in connection with thenccompanying drawings, is aspecification,l like characters on the drawings representing like parts.

My invention relates to pressure fluid motors, which may be of theimpact ty e, and more particularly to the valve mec anism forcontrolling the admission of the motive fluid to and exhaust fromthe'eylinder.

My invention will be best understood by.`

reference to the following specification, lwhen taken in connection withthe accompanying drawings of one illustrative embodiment thereof, whileits scope will be more particularly pointed out in the ap pended claims.

In the drawings:

Fi ure 1 is a central, longitudinal sectiona view, partly broken away,of a pressure fluid impact' motor embodying one form of my invention;

Fig. 2 is a sectional view, partly broken awa', on line 2--2 of Fig. 1;y,

Figa 3 is a sectional view on line 3'-3 of Fig. l; and

Figs. Ll and 5 are diagrammatic sectional views, in which all of theports and passages are brought into one plane, the better to illustratethe action of themotor; Fig: i showing the piston in its forwardposition and the valve in its rearward position; and Fig. 5 showing thepiston in its rearward position and t e valve in its forward position.

Referring to the drawings, and to the em.- bodimentoflmy invention whichI have selected for illustration, l have there. shown a' pressure `fluidmotor having a cylinder 6, in which a'1` piston 7reciproca'tes,.:'1`.his piston may be, and in the-Presentyfinstance is,

provided with a forwardly projecting-reduced portion 8, which mayconstltut'e a' piston rod to be connected to the working device to beactuated, or the reduced portion ma be used as a hammer to deliver asueces-"o1i of blows against any suitable impact receiving member, which1t is unnecessary herein to illustrate, as it forms noessentia part ofmy present invention.

The movements of the iston are controlled by a controlling valve 9,herein in the form of acylindrical shell located in a valve chamber,herein disposed at the rear of the cylinder4 chamber, and in linetherewith, such valve chamber being' herein provided by a two-part valveblock composed of a forward section 10 and a rear section 11. Bothsections of the valve block are seated within the walls of a suitablecasing 12, which-projects from a head-block 13,'

the rear portion of the latter bein broken away. The head-block isprovided with a supply chamber 14 forthe. motive lfluid, to which thelatter is constantly 'admitted from any suitable source of supplythrough a suppli1 passage 1'5. or the admission of motive fluid to theof 1 the cylinder chamber, thev valve chamber is provided with 'anannular admission groove 16, which has constant lcommunicaton with thesupply chamber 1 4, through a rearwardly extend' g passage or passagesv17.w i

`Zllhen in its rearward positioi (see Fig. 5), the rear end of the valveenters that portion of the vaelve chamber behind the admisrior of thevalve andthe rear of the cylinder chamber yfrom theniotive fluid. In theforward position of the valve, however (see 1 Figs. 1 and 4), theinteriorof the valve-is opened 'freely to theladmissio'n groove 16, sothat the motive fluid flows freely to the interior of the valve,andthence to the rear of the cylinder .chamber to drive the pistonforward.

The forward end of the c linder chamberl is supplied with motive luiwhen the valvii'v is at its rearward position -(see Fig. 5), by meansof,A oneuor more, herein two, return pressurepasspges 18 which extendlongitudmally 'througlwthe walls of the cylinder and open this passageextends through the valve/block section 10, andterminates in a lateralport 2 0 formed in the valve block 11 and opening into an annular valveblock oove 21.

-. In the rearward position o? the valve, the groove 21 is connectedwith the motive fluid supply by mcansof a circumferential valve groove22, the admission groove 16 into the cylinder chamber" y Athrough alaterallpbrt 19. At its rear end,

li co being cut away at 23., adjacent one or more of the admissionpassages 17 (see Figs. 1,

4 and 5), so as to give a sufficiently free admission of motive fluid tothe groove 21, by way of the valve groove 22, to return the piston. Fromthe groove 21, the motive fluid passes through the port 20, passages 18and port 19, to the forward end of the cylinder.

To exhaust motive fluid from the rear of the cylinder chamber, there isprovided in the valve block a `lateral exhaust port 24, which-opens intothe valve chamber. This lateral exhaust port lcommunicates with one ormore, herein three, longitudinal'exhaust passages 25, formed partly inthe cylinder` walls and extending rearwardly through y yboth sections ofthe valve block, and comential enlargement 27 workingY in anannumunicating witha. permanently open exhaast-port, or ports, 26 formedin the headblock.

The valve is;provide'd with a circumfer- A' lar chamber or groove 28 ofthe valve chamber,l the valve block being` provided with a, `lateralexhaust vport 2f) -leading from said groove to the exhaust passage 25.When the rvalve is in its rearward position (see Fig. 5), a prolongedportion 30 of the valve which extends" beyond -the circumferentialenlargement 27, lifts from its seat suiliciently to open the rear-of thecylinder chamber'toy the forward end of the valve chamber, thus placingthe rearof the cylinder chamber in communication with the exhaust port24. As shown in the drawin s, the port 24 is only partially uncovered ythe valve when inthis position, but such port may be, and

preferably is, of an elongated cross section (see Fig. 2), sothat bysuitably proportionin the port, the exhaust from the rear of the cyindex-. chamber niaybe made as free or restricted asA desired.

. fTo exhaust motive fluid from the forward end of the cylinderchamber,. the latter is provided with an exhaust port 31, adapted to, beuncovered by the piston before the completion of the rearward movementthere-` of, such port being connected with the longitudinal exhaustvpassages 25, and thereby with the atmosphere'. through the Perma--nently open exhaust opening 26. In addition to this, the forward end ofthe cylinder is maintained open for the exhaust of mtive fluid duringthe forward movement of the piston, after the closure of the port 31through the return port 19, passage 18, and port 20, the latter beingconnected through the valve chamber, lwhen the valve is posi,- tioned asshb'iwn in; 4, with the valve groove 22, chamber, 28, and exhaust port29,

ReferringA now more particularly to the provision for moving the valveto reverse the piston, 'the valve is provided with a rear en d portion32 of slightly reduced diameter having a sliding fit in thecorresponding reduced portion r33 of the valve chamber, be:

lup'to the time when it reaches the port 38,

yond the admission groove 16. This leaves a small, circumferentialshoulder 34, which constitutes a small pressure area constantly exposedto the motive fluid in the admission roove 16. On the other hand, theforward ace ofthe circumferential enlargement 27 constitutes an op osingdifferential pressure area, of relative y greater proportions.

When the valve is in its forward posi-- tion (see Figs. 1 und4), thesame is maintained in such position during the forward movement of thepiston by the pressure on the small area 34, augmented by 'the pressureonthe rearendarea 35-of the valve, there being no substantial pressureagainst the larger opposing 'pressure area' in the forward end of thechamber 28. To insure the absence of substaptial pressure against thislarger area at this time, there is herein provided a lateral port 36leading from the forward end ofthe chamber 28 to a longitudinal passage37, extending forwardly through the cylinder wall, and having at itsforward end a port 38, which is in com- 'the cylinder cham er with theexhaust port 31 and exhaust passage 25 leading to the pp'rlmanently openexhaust opening 26. en the piston is moving forwardly, and

the port 36, passage 37 andport 38, serve to exhaust any pressure fluidtrapped ,in the forward end of the chamber 28,.or entering thereinto byleakage fromY the cylinder chamber.

lVhen, however, the piston, during its forward stroke, passes beyond andcuts the port 38 off from communication with the exhaust port 31, thepassage 37 and port 36 are utiized to supfplyl pressure fluid to theforward end area' o t e enlargement 27, to cause a reversal of thevalve. To this end, the passage 37 is provided with'a lateral port 39,to 'which it will be convenient to refer as the intermittent pressureport, for the reason that pressure fluid is intermittently suppliedthereto to cause the reversal of the valve. Located substantially inline witlithis intermittent pressure port, is a constant pressure port40, the latter communicating constantly 1 1b throu h a longitudinallpassage 41 and latera port 42 with one of the rearwardly extendingpassages 17 leading to the constant pressure space 14.

As a means for intermittently establishing communication between theconstant pressure port 40 and the intermittent pressure port 39, thepiston is herein provided with a passage, herein in the form of anannular roove 43, which is so positioned that when This may take placeat any suitable point, but preferably occurs just prior to thestrikinfr-of the blow. 'Ifhe reversalv of the valve talies place, owingto the fact that the pressure upon the large opposing differential areaexceeds that'on the small area 34 plus the end area 35 of the valve, andthus causes the latter to be quickly shifted to the position shown inFig. 5. As above described, this admits motive fluid to the forward endof the cylinder chamber, and opens the rear end thereof to the exhaustso that the-piston, having made its working stroke, moves back on itsreturn stroke. V

The piston carries, projecting from its 'rear` end, a plug portion 44,which in the illustrated embodiment of my invention, is of "lesserdiameter' than the piston itself. This plug portion is ada ted toproject out an Iaperture 45 in the valve 'it preferabl of'and beyond thecylin er chamber in the rearward position of-the4 valve, andthrough lug,in which has` a` lsliding t, and which constitutes `t e means ofcommunication be- 't'ween th'ewvalve chamber. and the piston chamber,`

The valve. having been reversed, the pis ton during its returnmovementexpels the exh'austmotivefluid at the rear of the cylin- 4der chamber,through ,the exhaust port 24.

` During this movement of the piston, the-supply of motive 'fluid'to thechamber 28 is continued for a time, or-until the forward edge of thepion `glroo've' 43 has passed rear-- wardly beyond t e intern'iittentlpressure port 39, thus cutting olf the latter from the constant pressureport 40. Air under pressure is now trapped 'in the passage. 37, port 36,and chamber 28, which, acting against the forward area of theenlargement 27 and in conjunction with the' exhaust pressure acti ing onthe forward end of the reduced portion 30 'of the valve,'continues tohold the latter in its rearwardpositiom When, however, the forward endof the piston, in its rearward travel, reaches the intermittent pressureport 39, the latter is placed in communication with the forward exhaustport v the portion 44 entering the same.

31, whereby the pressure on the large differential area of theenlargement 27 of the valve is exhausted.'

' The valve is thus held reversed preferably after the plug portion 44enters the aperf ture 45. When the piston, however, reaches some suchposition as is represented in Figs. 1 and 4, (the valve still'being inthe posi'- tion' shown in Fig. 5), a fluid cushion is formed between theendv of the piston and the opposing face' of the valve block, by reasonof the closure of the apex-ture 45 by This brings the piston to rest,and prevents, it from striking the valve block. should the valve Vfailto reverse. About the s-.une time, however, the remaining motive fluidhaving Leccese b also opened to the exhaust valve through the chamber byway of the port 19, return passage 18, port.20, valve groove 22, chamber'28,' and port 29, this condition holding until the valve is againreversed. ,The valvewhen reversed, is securely held-in its forward poSitio'n, since the. port 36, passage 37, and port 38, relieve the largerpressure area of the pressure Vof any accumulated motive fluid.

lVhile the length Aof the projecting '.plug portion 44 might bereduced'so as not to project within the valve in the rearmost po sitionofthe piston, herein, for` the ksake of reducing the clearance withinthe valve chamber, it is somewhat prolonged as Shown in the drawings, sothat it not only passes through and closes the port-like aperture 45,but also enters part wayV into the valve itself. The interior diameterof the valve, however, is made sli htly greater than the exteriordiameter o the plug, so that a small clearance space remains between thevalve and the entering portion of 'the plug. This permits the motivefluid trapped within the valve chamber to escape back and about thesides of the plug to the exhaust port 24,'

when the plug enters the valve. Such escape, moreover, may befacilitated, if desired.

by any suitable formation of the plug, such for example as the provisionof one or more longitudinal grooves 46, cut part Way along the surfaceof the plug. These grooves, moreover, have another function which is ofconsiderable importance. starts upon its forward movement, motive fluidacts against the area of the plug 44, but when the forward ends of Vthegrooves 46 pass forwardly beyond the aperture 45 and enter the rearportion of the cylinder chamber, the latter immediately receivesimotivefluid through lthe grooves, and such motive fluid at oice acts upon thefull area of the pist-on,'tl1e1'cby insuring a quick and powerful actionat the part o'l the stroke where it is most needed. 'V

The desvribed foi-rn of valve, being 'very delicately balanced, actsquickly to reverse at the close of the rearward'piston move ment, sothat a very high speed and very powerful blow can be secured throughils,

When the piston the cylinder and valve chamber being reduce to aminimum, a very high elliciency can be obtained.

It will be observed that the valve being located in a separate chamber,behind the piston chamber and between the latter and the head-block, itis not necessary for the operation of the tool that any part of thepiston enter the valves. Herein, the plug 44, carried by the piston, iscaused to enter the valve chamber 'to reduce the clearance therein, butsucli is not essential. The clearance within the. valve chamber might bereduced by making the valve solid except for a central axial passagethrough the same, or with a valve proportioned as. shown,- a stationaryplug might be employed projecting forwardly within.- the valve'from thcvalve block section 11.

While I have herein shown and described one specific embodiment of myinvention for illustrative purposes, and have disclosed and discussed indetail the construction and arrangement incidental yto one s ecificapplication thereof,` it is to be un erstood that the invention islimited neither to the mere` pressure area, a forwardextensionextendingforwardly from the larger pressure area; means for supplying motivefluidconstantly to said smaller area; a chamber in which the largerannular projection works; means ncluding a constant pressure port, anint-ermittent pressure port, a passage leading from said intermittentpressure port to-said chamber, anda piston having a groove to connectsaid ports for intermittently supplying motive fluid to and exhaustingit from said chamber thereby to lcause the. larger pressure areaintermittently to predominate over the smallerthereby to e'ect thereversal of the valve; means for supplying motive fluid to the interiorof said valve at its rear end to drive said piston forward; meansconports 2 4 and 29.

trolled by said valve t0 exhaust the rear end of said piston during itsrearward'stroke.

2. A pressure fluid motor having an ani nular valve provided withdifferential presfor supplying motiverfluid to the interior of saidvalve at its rea-rV en d to drive said piston forward; means'controlled`by said valve for .supplying motive fluid to the forward end of Saidpiston to drive. it rearward; means to exhaust the forward end of thepiston duringa part ofits forward stroke; means controlled .by saidvalve to exhaust the forward end of said piston.during a. remaining'partoiits forward stro-ke; and means controlled by said valve to exhaust therear end of said piston. during its rearward stroke.

A, 3. A- pressure fluid im act motor having a hollow valve9 provide withthe enlarge ments 27 ,and 34 and the forwardand rearward extensionsythepiston 7 provided with the groove .143; and the cylinder provided withthe consta-nt pressure space 14; the

A,valve chamber with its extension 133; the

groove 28 in whigh the enlargement works; the passage 37 with its ports36, 38 and 39; the paage 18 with its ports'19and'f20'; the passage 4lwith its port 40; theexli'aust passage'25 lwith its portV 31; and theexhaust 4. A pressure fluid motor havin a piston anannular valve rovidedwith differential ressure areas, a orward extension extend-a.. mg beyondthe larger pressure area, a rearward extension extending beyondthesmaller pressure area, a pocket 33`for' s aid rearward extension;means for supplyingmotive fluid constantly to said smaller areaglineansincluding a constant prsure port, an intermittent pressure port and agroove 43 'in said piston to connect said ports Vfor intermittentlysupplying motive fluid to and eX- hausting it from said larger pressurearea; means for supplying motive fluid Vto the interior of said valve atits rear 'end to vdrive said'piston forward; means controlled by saidvalve'for supplying motive fluid to the forward end of said piston todrive it rearn ward; means to exhaust the forward end of' the piston;and means controlled by sai valve to exhaust the rear end of sai-idpiston during its rearward stroke. a u

5. A lpressure .fluid motor having: a pis- .am annular valve providedwith differ Jal pressure arcas, a forward extension lending beyond the.larger pressure area,

larger pressure area; 4motive fluld to the interior of said valve at ararward extension extending beyond the smaller pressure area. a pocket2&3 for said rearward extension; means l'or supplying motivi` fluidconstantly lo said smaller area; means including a constant pressureport. au intermittent. pressure port and a groove 43 in said piston toconnect said ports for intermittently supplying motive fluid to andexhausting it from said larger pressure area; means for supplying motivefluid to the'interior of said valve at its rear end to drive said pistonforward; means controlled bysaid valve for supplying motive fluid to theforward end' of said piston to drive it rearward; means controlledbysaid valve to exhaust the forward end of the piston; and meanscontrolled by said valve to exhaust the rear, end of' said piston duringits rearward stroke. i

(i. A pressure fluid motor having a plston posed extension; an annularvalve surrounding said reduced rearwardly disposed extension andprovided with differential pressure areas, a fbi-ward extensionextending beyond the larger pressure area; means for supplying motivefluid constantly to the sm'aller'area; means' including!` a constantpressure port, an intermittent pressure port and a groove 43 in saidpiston to connect said ports for tive fluid to and exhausting it fromsaid means for supplying its rear end to drive said piston forward;means controlled by said valve for Vsupplying'nlotive fluid to theforwardend of said piston to driveit rearward; means to exhaust theforward end ofthe piston; and meaus'controlled by said valve to exhaustthe rear end of said piston during its rearward stroke.

7.A Alpressure fluid motor having a uiston; antannular valve providedwith di erential pressure areas, a forward extension extending beyondthe larger pressure area, means for supplying motive fluid constantly tothe smaller pressure'area; means inclu ing a constant pressure port, anintermittent pressure port, and a groove 43 in said piston to connectsaid ports for intermittently supplying motive fluid to and exhaustmg itfrom said larger pressure area; a constantly open exhaust port forexhausting such pres- `piston during its provided with a, reducedrearwardly disintermittently supplying mo-v sure fluid as is opposed toshifting of said valve by pressure on said larger pressure area; meansfor supplying motive fluid to the interior of said valve at its rear undto drive said piston folnvard; means conti-oiled by said valve forsupplying motive Huid to the forward end of said piston to drive itrearward; means to exhaust the forward end of -the piston; and meanscontrolled by said valve to exhaust. the rear end of said rearwardstroke.

8. A pressure uid motor comprising in kombination a cylinder, a pistontherefor haying a rearwardly extending reduced ,pertion,an annular valvebavinga longitudi nally4 disposed opening therein into which saidreduced portion ente-rs during a portion of the return stroke of saidpiston. and live pressure fluid actuated means for moving said vulvealternately into two .positions and for holdingsaid valve in each ofsaid positions pending reversal of s id valve by said live pressurefluid actuate means.

' tt. pressure fluid impact motor having a piston;

means to cause said valve. tn abe moved in 'opposite directions by livepressure fluid:

its cylinder; an annular valve;

means for closing the' rear en d of said valve inits real-most position;means for causing 't motive fluid topass through said valve to drivesaidpiston forward"when said valve is in it-s forward position; meansunder the control of said valve for exhausting the motive fluid fromthe. rear of said`piston; means for exhausting `the motive. fluid fromthe front end ofsaid piston -during a portion of its forwardstroke-ilu-.huling au exhaust. portin `the main Vall of tin` cylinderindependent of said valve-and adapted t'o be closed by said pistonduring the forward stroke thereof; and supplemental Vmeans under thecontrol of said valve for exhausting the motive Huid from the front endof said piston after the closure of said exhaust port during a remainingportion of the forward stroke of. said piston.

In testimony whereof, I have signed my name to thisspecifcation, in thepresence of two subscribing witnesses.

GEORGE H. GILMAN.

Witnesses:

C. J. JONES, G. H: JENKS.

